Broadband MIMO dielectric resonator antenna

Abstract

The invention provides a broadband MIMO dielectric resonator antenna, and belongs to the field of radio frequency antennae, the broadband MIMO dielectric resonator antenna comprises a dielectric substrate, a floor and radiators which are sequentially distributed from bottom to top, the lower surface of the dielectric substrate is provided with a microstrip feeder line, the floor is provided with a coupling slot, a plurality of radiators are symmetrically distributed along the transverse direction and the longitudinal direction, and the floor between adjacent radiators is provided with a DGS structure. The radiator comprises a first dielectric block and a second dielectric block which are stacked, the first dielectric block and the second dielectric block work in the same mode, the first dielectric block covers the coupling gap, the second dielectric block is located on the upper surface of the first dielectric block, an arc-shaped annular patch is arranged on the upper surface of the second dielectric block, and signals are transmitted to the coupling gap through the microstrip feeder line. The radiation body is fed through the coupling gap; the radiator adopts the dielectric block I and the dielectric block II which are designed in a stacked manner, so that the gain and the bandwidth of the antenna can be improved, and the antenna has a good impedance matching characteristic; the DGS structures are arranged between the adjacent radiators, so that coupling between the adjacent antennas can be removed.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency antennas, and in particular to a broadband MIMO dielectric resonator antenna. Background Art

[0002] Antennas are an essential component of radio frequency systems. Their radiation efficiency, impedance matching, and other indicators determine the transmission quality of the entire communication link. With the rapid development of 6G mobile communication technology, system design faces multiple technical challenges.

[0003] First, with the continuous growth of communications services, sub-6 GHz frequency band resources are becoming increasingly scarce. This frequency band is widely used in existing communications systems due to its excellent propagation characteristics and low signal attenuation. However, the gradual saturation of frequency band resources has made achieving efficient antenna radiation within the limited frequency band a key factor in increasing channel capacity.

[0004] Secondly, with the trend toward miniaturization and integration of communication equipment, the distance between antenna elements is shrinking. The continued reduction in spacing between elements in multiple antenna arrays has significantly increased mutual coupling. This effect can alter key parameters such as the antenna's directivity pattern, gain, and impedance matching, thereby impacting signal transmission quality and overall system performance. Therefore, reducing coupling between antennas, improving antenna diversity, and thereby enhancing the overall communication system's anti-interference capabilities, are critical issues that urgently need to be addressed.

[0005] Furthermore, with the rapid development of wireless electronic devices, the operating frequency bands used by different electronic devices have also varied. To meet diverse communication needs, a single antenna needs to achieve good radiation characteristics and impedance matching across a wide frequency band. This design not only significantly reduces the size of the RF transceiver but also improves the compatibility and flexibility of the device, thereby meeting the needs of different device application scenarios. Therefore, the design of broadband antennas has become particularly important.

[0006] In the prior art, the Chinese invention patent application "Filtering Dielectric Resonator Antenna with Dual Radiation Zeros" with publication number CN109687113A uses a dielectric resonator as the antenna's radiator, and introduces a second dielectric plate to improve the antenna's matching performance, thereby stimulating three operating modes of the dielectric resonator, thereby effectively widening the antenna's bandwidth. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: how to achieve a lower coupling coefficient between antenna units while maintaining broadband antenna impedance matching.

[0008] The present invention solves the above-mentioned technical problems through the following technical solutions: a broadband MIMO dielectric resonator antenna, the antenna comprising a dielectric substrate, a floor, and a radiator, which are sequentially arranged from bottom to top; a microstrip feeder is provided on the lower surface of the dielectric substrate; a coupling slot is provided on the floor; a plurality of radiators are symmetrically distributed in the transverse and longitudinal directions; a DGS structure is provided on the floor between adjacent radiators; the radiator comprises a stacked dielectric block 1 and a dielectric block 2, the dielectric block 1 and the dielectric block 2 operating in the same mode; the dielectric block 1 covers the coupling slot; the dielectric block 2 is located on the upper surface of the dielectric block 1; an arc ring patch is provided on the upper surface of the dielectric block 2; a signal is transmitted to the coupling slot via the microstrip feeder, and the radiator is fed via the coupling slot.

[0009] Beneficial effects: In the broadband MIMO dielectric resonator antenna of the present invention, the radiator adopts a stacked dielectric block 1 and a dielectric block 2, and the dielectric block 1 and the dielectric block 2 operate in the same mode. Since the two dielectric blocks operate in the same or similar frequency band, the gain and bandwidth of the antenna can be improved, and the return loss of the antenna is less than 10 dB in the operating frequency band of 4-6 GHz, and has good impedance matching characteristics. By providing a DGS structure on the floor between adjacent radiators, the coupling between adjacent dielectric resonator antennas can be eliminated, and the antennas have good isolation characteristics within the operating frequency band, and the coupling coefficient is less than -15 dB. By providing an arc ring patch on the upper surface of the dielectric block 2, the impedance matching can be adjusted, further improving the impedance matching characteristics of the antenna.

[0010] Preferably, dielectric block 1 and dielectric block 2 both operate in HEM11 mode, are made of different materials, are both cylindrical in shape and have the same height, and the diameter of dielectric block 2 is greater than that of dielectric block 1.

[0011] Preferably, the material of dielectric block 1 is Rogers 3010, with a dielectric constant of 10.2, and the material of dielectric block 2 is Rogers 3006, with a dielectric constant of 6.15.

[0012] Preferably, the antenna further comprises at least two metal posts, the central axes of the dielectric block 1 and the dielectric block 2 coincide with each other, and the metal posts penetrate the dielectric block 1 and the dielectric block 2 to fixedly connect the two.

[0013] Beneficial effect: The present invention provides a metal column that passes through the dielectric block 1 and the dielectric block 2, thereby firmly connecting the two together.

[0014] Preferably, a T-shaped gap and rectangular gaps on both sides of the T-shaped gap are provided on the floor between adjacent radiators distributed along the horizontal direction, and a dumbbell-shaped gap is provided on the floor between adjacent radiators distributed along the vertical direction. One side of the T-shaped gap and the rectangular gap are respectively connected to the outer edge of the floor. Rectangle 1 in the T-shaped gap is located in the middle of the adjacent coupling gaps, and the length of rectangle 1 is greater than the length of the coupling gap.

[0015] Preferably, the outer edge of the arc-shaped patch is aligned with the outer edge of the dielectric block 2.

[0016] Preferably, the dielectric substrate is rectangular, made of Rogers 5880, and has a dielectric constant of 2.2.

[0017] Preferably, the microstrip feed line is rectangular, one end of the microstrip feed line is connected to the outer edge of the dielectric substrate, and the other end of the microstrip feed line is located directly below the coupling gap. A low-impedance microstrip line is provided on the microstrip feed line, and the width of the low-impedance microstrip line is greater than the width of the rectangle.

[0018] Beneficial effects: The present invention can form a high-low impedance microstrip line by setting the width of the low-impedance microstrip line to be greater than the width of the rectangle of the microstrip feeder. By changing the width of the low-impedance microstrip line and the width of the microstrip feeder, the impedance matching can be adjusted.

[0019] Preferably, a dual-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate, and then the dual-port MIMO antenna is translated symmetrically along the length direction of the dielectric substrate to obtain a MIMO antenna with an even number of ports; or a multi-port MIMO antenna is obtained by translationally symmetrically shifting a radiator along the length direction of the dielectric substrate, and then the multi-port MIMO antenna is mirrored along the width direction of the dielectric substrate to obtain an even-number-port MIMO antenna.

[0020] Preferably, a dual-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate, and then an eight-port MIMO antenna is obtained by translating the dual-port MIMO antenna along the length direction of the dielectric substrate; or a four-port MIMO antenna is obtained by translating a radiator along the length direction of the dielectric substrate, and then an eight-port MIMO antenna is obtained by mirroring the four-port MIMO antenna along the width direction of the dielectric substrate.

[0021] The advantages provided by the present invention are: the peak gain of the antenna of the present invention is higher than 5dBi in the 5-6GHz range, the maximum gain is greater than 6dBi, the envelope correlation coefficient is less than 0.05 in the 4-6GHz frequency band, the antenna system of the present invention has good diversity characteristics, the antenna structure is simple, and it has good practical value in mobile communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0023] Figure 2 A bottom view of a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a floor in a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of return loss simulation results for eight ports of a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of simulation results of coupling coefficients between eight ports in a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0027] FIG6( a ) is a radiation pattern of the broadband MIMO dielectric resonator antenna at 4.5 GHz in the XOZ plane provided by an embodiment of the present invention;

[0028] FIG6( b ) is a YOZ plane radiation pattern of a broadband MIMO dielectric resonator antenna provided in an embodiment of the present invention at 4.5 GHz;

[0029] FIG7( a ) is a radiation pattern of the broadband MIMO dielectric resonator antenna at 5.5 GHz in the XOZ plane provided by an embodiment of the present invention;

[0030] FIG7( b ) is a YOZ plane radiation pattern of a broadband MIMO dielectric resonator antenna provided in an embodiment of the present invention at 5.5 GHz;

[0031] Figure 8 A peak gain diagram of a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0032] Figure 9 A schematic diagram of the envelope correlation coefficient of a broadband MIMO dielectric resonator antenna provided by an embodiment of the present invention;

[0033] In the figure: 10 dielectric substrate, 11 microstrip feed line, 12 low impedance microstrip line, 20 floor, 21 coupling slot, 22 T-shaped slot, 221 rectangular slot, 23 rectangular slot, 24 dumbbell slot, 241 rectangular slot, 242 rectangular slot, 31 dielectric block 1, 32 dielectric block 2, 33 circular arc ring patch, 40 metal column DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following describes the technical solutions of the present invention clearly and completely with reference to specific embodiments and the accompanying drawings. It is obvious that the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, this embodiment provides a broadband MIMO dielectric resonator antenna. The antenna includes a dielectric substrate 10, a floor 20, and a radiator, which are arranged in sequence from bottom to top. A microstrip feed line 11 is provided on the lower surface of the dielectric substrate 10, and a coupling slot 21 is provided on the floor 20. Multiple radiators are symmetrically distributed in the horizontal and vertical directions. A DGS structure is provided on the floor 20 between adjacent radiators. The radiator includes a stacked dielectric block 1 31 and a dielectric block 2 32. The dielectric block 1 31 and the dielectric block 2 32 operate in the same mode. The dielectric block 1 31 covers the coupling slot 21, and the dielectric block 2 32 is located on the upper surface of the dielectric block 1 31. The upper surface of the dielectric block 2 32 is provided with an arc ring patch 33. The signal is transmitted to the coupling slot 21 via the microstrip feed line 11, and the radiator is fed through the coupling slot 21.

[0036] It should be noted that the multiple radiators are symmetrically distributed in the horizontal and vertical directions. The horizontal direction refers to Figure 1 The Y-axis direction shown in the figure is the vertical direction. Figure 1 The X-axis direction shown in FIG is parallel to one side of the dielectric substrate 10 , and the Y-axis direction is parallel to the other side of the dielectric substrate 10 .

[0037] In the broadband MIMO dielectric resonator antenna of the present invention, the radiator adopts a stacked dielectric block 1 31 and a dielectric block 2 32. The dielectric block 1 31 and the dielectric block 2 32 work in the same mode. Since the two dielectric blocks work in the same or similar frequency band, the gain and bandwidth of the antenna can be improved. Figure 4 It can be seen that the return loss of the antenna is less than 10dB in the operating frequency band of 4-6GHz, and has good impedance matching characteristics. By setting a defective ground (DGS) structure on the floor between adjacent radiators, the coupling between adjacent dielectric resonator antennas can be eliminated. Figure 5 It can be seen that the antennas have good isolation characteristics within the working frequency band, and the coupling coefficients are all lower than -15dB; using a patch to cover the dielectric resonator antenna will change the impedance matching and radiation characteristics of the antenna. By providing an arc ring patch 33 on the upper surface of the dielectric block 2 32, it can be well matched with the feeding gap and microstrip line of the floor to achieve broadband impedance matching characteristics of the antenna.

[0038] Both dielectric block 1 31 and dielectric block 2 32 operate in HEM11 mode, with radiation patterns pointing upward. Made of different materials, both are cylindrical in shape and have the same height. The diameter of dielectric block 2 32 is larger than that of dielectric block 1 31. In this embodiment, dielectric block 1 31 is made of Rogers 3010 with a dielectric constant of 10.2, while dielectric block 2 32 is made of Rogers 3006 with a dielectric constant of 6.15. The heights of dielectric blocks 1 31 and 32 are both 10 mm. The radius of dielectric block 1 31 is 7.5 mm, while the radius of dielectric block 2 32 is 10 mm. In order to design two dielectric blocks with different dielectric constants to operate in similar frequency bands as much as possible and to both operate in HEM11 mode, the radius of the upper dielectric block with the lower dielectric constant is increased, thereby enabling both dielectric blocks to operate in the same mode and frequency band.

[0039] Continue to see Figure 1 The antenna also includes at least two cylindrical metal pillars 40 with a radius of 0.25 mm. When dielectric block 1 31 and dielectric block 2 32 are stacked, their central axes coincide. Metal pillars 40 penetrate dielectric block 1 31 and dielectric block 2 32 to securely connect them.

[0040] The minimum distance between two adjacent dielectric blocks 2 32 is 10 mm. T-shaped slots 22 and rectangular slots 23 on either side of the T-shaped slots 22 are provided on the floor 20 between adjacent radiators distributed horizontally. Dumbbell-shaped slots 24 are provided on the floor 20 between adjacent radiators distributed vertically. One side of the T-shaped slots 22 and rectangular slots 23 are respectively connected to the outer edge of the floor 20. The upper, thin rectangular slot 221 of the T-shaped slot 22 is connected to the outer edge of the floor through the lower rectangular slot. Both the T-shaped slot 22 and the rectangular slot 23 serve as external slots connected to the outer edge of the floor. The thin rectangular slot 221 of the T-shaped slot 22 is located between adjacent coupling slots 21. The line width w2 of the thin rectangular slot 221 is greater than the line width w1 of the coupling slot 21. In this embodiment, the line width w2 of the thin rectangular slot 221 is 3.8 mm, while the line width w1 of the coupling slot 21 is 2.2 mm.

[0041] The present invention utilizes two different defective ground structures to eliminate coupling between antennas. To eliminate coupling between antennas in the X-axis, the present invention uses a dumbbell-shaped defective ground structure consisting of two wider rectangles and a narrower rectangle in the middle. To eliminate coupling between antennas in the Y-axis, the present invention uses a T-shaped defective ground structure with two rectangular defective ground structures on either side. This defective ground structure effectively reduces surface wave propagation between antenna elements and extends the current path in the floor, thereby reducing coupling between antennas.

[0042] The following describes the sizes of the various gaps. Figure 3 The coupling gap 21 has a length W1 of 8.6mm and a width L1 of 2.3mm. The T-shaped gap 22 has a height L2 of 16mm and a width W3 of 4.16mm. The upper, thin rectangle 1 221 has a length W2 of 29mm. The rectangular gaps 23 on either side have a length L3 of 8.6mm and a width W4 of 2mm. The dumbbell-shaped gap 24 is formed by connecting the larger rectangles 241 on either side and the thinner rectangle 3 242 in the middle. The overall length W5 of the dumbbell-shaped gap 24 is 25mm and the width L4 is 2.42mm. The rectangles 241 on either side of the dumbbell-shaped gap 24 have a length L5 of 12.7mm and a width W6 of 4.2mm.

[0043] The outer edge of the arc-shaped patch 33 is aligned with the outer edge of the dielectric block 2 32. The arc-shaped patch 33 can be made of copper foil, with an outer radius of 10 mm and an inner radius of 7.5 mm.

[0044] The dielectric substrate 10 is rectangular, with dimensions of 120 mm×60 mm×0.762 mm, and is made of Rogers 5880 with a dielectric constant of 2.2.

[0045] See also Figure 2 The microstrip feed line 11 is located on the back of the rectangular dielectric substrate 10 and is composed of microstrip lines of varying widths. The microstrip feed line 11 is rectangular, with one end connected to the outer edge of the dielectric substrate 10 and the other end located directly below the coupling slot 21. A low-impedance microstrip line 12 is provided on the microstrip feed line 11, and the width of the low-impedance microstrip line 12 is greater than the width of the rectangle. Because the low-impedance microstrip line 12 is wider than the rest of the microstrip line, it can form microstrip lines with high and low impedances. By varying the width of the low-impedance microstrip line 12 and the width of the microstrip feed line 11, impedance matching can be adjusted.

[0046] A dual-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate 10, and then the dual-port MIMO antenna is translated symmetrically along the length direction of the dielectric substrate 10 to obtain a MIMO antenna with an even number of ports. Alternatively, a radiator can be translated symmetrically along the length direction of the dielectric substrate 10 to obtain a multi-port MIMO antenna, and then the multi-port MIMO antenna is mirrored along the width direction of the dielectric substrate 10 to obtain an even-number of ports MIMO antenna.

[0047] Continue to see Figure 1The unit antenna and the decoupling structure of the present invention both adopt a symmetrical structure, which is beneficial to the extension of the multi-port MIMO antenna. The antenna of the present invention can be effectively expanded to MIMO with even-numbered ports such as four-element, six-element or ten-element. Antenna. Taking the eight-element MIMO dielectric resonator antenna as an example, a two-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate 10, and then the two-port MIMO antenna is translated symmetrically along the length direction of the dielectric substrate 10 to obtain an eight-port MIMO antenna. Alternatively, a radiator can be translated symmetrically along the length direction of the dielectric substrate 10 to obtain a four-port MIMO antenna, and then the four-port MIMO antenna is mirrored symmetrically along the width direction of the dielectric substrate 10 to obtain an eight-port MIMO antenna.

[0048] Using electromagnetic simulation software Ansys Electronics Desktop 2021 Figure 1 The eight-element MIMO dielectric resonator antenna shown in the figure is simulated. The antenna operates in the frequency band range of 4GHz-6GHz and the relative bandwidth is 40%. Figure 4 It can be seen that the antenna's return loss is less than 10dB in the 4-6GHz operating frequency band, and it has broadband characteristics and good impedance matching characteristics. Figure 5 The isolation between the antenna ports is shown. It can be seen that the antennas have good isolation characteristics within the working frequency band, and the coupling coefficients between the eight ports are all lower than -15dB. Figure 8 It can be seen that the antenna has good radiation characteristics. The peak gain of the antenna is higher than 5dBi in 5-6GHz, and the highest gain is greater than 6dBi. Figure 9 It can be seen that the envelope correlation coefficient is less than 0.05 in the 4-6 GHz frequency band. Therefore, the broadband MIMO dielectric resonator antenna system of the present invention has good diversity characteristics, a simple antenna structure, and good practical value in mobile communications.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A broadband MIMO dielectric resonator antenna, characterized by: The antenna includes a dielectric substrate, a floor, and a radiator, which are arranged in sequence from bottom to top. A microstrip feeder is provided on the lower surface of the dielectric substrate, a coupling slot is provided on the floor, and multiple radiators are symmetrically distributed in the horizontal and vertical directions. A DGS structure is provided on the floor between adjacent radiators. The radiator includes a stacked dielectric block 1 and a dielectric block 2. Dielectric block 1 and dielectric block 2 operate in the same mode. Dielectric block 1 covers the coupling slot, and dielectric block 2 is located on the upper surface of dielectric block 1. An arc ring patch is provided on the upper surface of dielectric block 2. Signals are transmitted to the coupling slot via the microstrip feeder, and are fed to the radiator via the coupling slot.

2. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: The dielectric block 1 and the dielectric block 2 both work in the HEM11 mode. They are made of different materials, are both cylindrical in shape and have the same height. The diameter of the dielectric block 2 is greater than that of the dielectric block 1.

3. The broadband MIMO dielectric resonator antenna according to claim 1 or 2, characterized in that: The material of dielectric block 1 is Rogers 3010 with a dielectric constant of 10.2, and the material of dielectric block 2 is Rogers 3006 with a dielectric constant of 6.

15.

4. The broadband MIMO dielectric resonator antenna according to claim 2, wherein: The antenna also includes at least two metal columns. The central axes of the dielectric block 1 and the dielectric block 2 coincide with each other. The metal columns penetrate the dielectric block 1 and the dielectric block 2 to fixedly connect the two.

5. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: A T-shaped gap and rectangular gaps on both sides of the T-shaped gap are provided on the floor between adjacent radiators distributed in the transverse direction. A dumbbell-shaped gap is provided on the floor between adjacent radiators distributed in the longitudinal direction. One side of the T-shaped gap and the rectangular gap are respectively connected to the outer edge of the floor. Rectangle 1 in the T-shaped gap is located in the middle of the adjacent coupling gap, and the length of rectangle 1 is greater than the length of the coupling gap.

6. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: The outer edge of the arc ring patch is aligned with the outer edge of the dielectric block 2.

7. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: The dielectric substrate is rectangular, made of Rogers 5880, and has a dielectric constant of 2.

2.

8. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: The microstrip feed line is rectangular, one end of the microstrip feed line is connected to the outer edge of the dielectric substrate, and the other end of the microstrip feed line is located directly below the coupling gap. A low-impedance microstrip line is provided on the microstrip feed line, and the width of the low-impedance microstrip line is greater than the width of the rectangle.

9. The broadband MIMO dielectric resonator antenna according to claim 1, wherein: A dual-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate, and then the dual-port MIMO antenna is translated symmetrically along the length direction of the dielectric substrate to obtain a MIMO antenna with an even number of ports; Alternatively, a radiator is translated symmetrically along the length direction of the dielectric substrate to obtain a multi-port MIMO antenna, and then the multi-port MIMO antenna is mirrored symmetrically along the width direction of the dielectric substrate to obtain an even-number-port MIMO antenna.

10. The broadband MIMO dielectric resonator antenna according to claim 1 or 9, characterized in that: A dual-port MIMO antenna is obtained by mirroring a radiator along the width direction of the dielectric substrate, and then the dual-port MIMO antenna is translated symmetrically along the length direction of the dielectric substrate to obtain an eight-port MIMO antenna; or a four-port MIMO antenna is obtained by translationally symmetrically shifting a radiator along the length direction of the dielectric substrate, and then the four-port MIMO antenna is mirrored symmetrically along the width direction of the dielectric substrate to obtain an eight-port MIMO antenna.

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